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When does NPH insulin peak?

Medically reviewed by Last updated on Oct 20, 2022.

Official answer


The peak time of insulin is the time it is working the hardest to lower your blood glucose.

NPH insulin is an intermediate-acting insulin that usually starts to work (has an onset) about 1 to 3 hours after injection, peaks 4 to 12 hours later, and is effective for about 12 to 16 hours.

However, it's important to remember that the onset and duration of action of any insulin may vary individually or at different times in the same individual. Brand names of NPH insulin include Humulin N and Novolin N.

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